Evidence-poor medicine: just how evidence-based are Australian clinical practice guidelines?

BACKGROUND: Clinical practice guidelines aim to assist medical practitioners in making efficient evidence-based decisions in daily practice. However, international studies have shown that the majority of recommendations in American and European guidelines are not based on strong evidence. AIMS: To review Australian clinical practice guidelines across a broad range of high-impact conditions and determine how evidence-based they are. METHODS: Australian guidelines published from January 2010 to May 2018 relating to the top 10 causes of death in Australia were identified from the National Health and Medical Research Council (NHMRC) clinical practice guideline database and other relevant sources. The graded recommendations in these guidelines were extracted for analysis and the systems used for grading the recommendations were recorded. RESULTS: Ten relevant Australian guidelines were identified, containing a total of 748 graded recommendations. All 10 guidelines used either the Grading of Recommendations Assessment, Development and Evaluation (GRADE) or NHMRC systems to assess recommendations. However, only 18% (n = 136) of these recommendations were based on Level I (or equivalent) evidence; 25% (n = 185) were based on Level II evidence, 29% (n = 218) on Level III, and 9% (n = 66) on Level IV. Consensus-based recommendations accounted for 19% (n = 143) of all recommendations. CONCLUSIONS: Despite the enthusiasm of the evidence-based medicine movement and its documented successes, contemporary medicine appears to remain largely evidence-poor, not evidence-based. Future research should aim to provide reliable descriptions of what constitutes valid clinical reasoning in evidence-poor situations.